The overwhelming belief prior to microbiome research was that a mother’s breast milk was sterile. Researchers believed that milk could only be cultured when a woman had mastitis, an infection of the breast tissue. Yet, one researcher who began studying breast milk microbiome in the 1990s found that the opposite is true: breast milk actually serves as a potential source of microbes to infants. The scientific community believed that he studied samples contaminated from the mothers’ skin or babies’ mouths; however, the bacterial strains found in the breast milk did not exist in either mouth or skin communities. His team later confirmed that the bacteria found in the breast milk were found in the infant gut microbiome.

Later in 2011, another team of researchers characterized the human breast milk microbiome from 16 women and found extremely diverse microbial communities. While samples varied from woman to woman, the most abundant bacteria were found to be Streptococcus, Staphylococcus, Serratia, and Corynebacteria. The variation in samples reveals that the mother passes on her microbiome to her offspring, essentially training the immune system and expanding the infant’s exposure.

Researchers now question the affects these various microbial sources have on infants. One primate study published in Nature Communications revealed that macaques on a high fat diet throughout pregnancy and lactation birthed babies with altered gut microbiomes. Although researchers are not sure what exactly causes these changes, they think breastfeeding is a key and critical component not only to the introduction and influence on the infant gut microbiome but also how it changes its metabolism.

Breast Milk Microbiome: researching a mother’s microbial role

Although we know that the mother’s microbes affect newborns, the microbial communities found within the placenta, vagina, and breast milk are neglected when it comes to fetal and infant development. However, the medical field has recognized that the mother’s microbiome plays an important role for women’s health. One rodent study in 2012 found that changes in the gut microbiome during pregnancy may be linked to weight gain and reductions in insulin sensitivity.

One scientist hypothesized that breast milk microbiome is critical to the health of the mother. Mastitis, an infection that causes severe pain, is typically treated with antibiotics. His research observed significant sample-to-sample dysbiosis of the breast-milk microbiome. A single pathogenic strain of bacteria dominated each sample and the genus Lactobacillusdisappeared from the samples altogether.

Lactation researchers at the Washington State University recently confirmed these results in an additional study, which collected breast milk microbiome samples from another group of women. The majority of samples from women who complained of pain or discomfort in the breast or who had recently taken antibiotics were dominated by a single strain and once again lacked Lactobacillus.

With this study, researchers questioned whether the bacteria found in the dysbiotic milk originated in the gut. Women took supplements containing the depleted bacteria and then found those specific strains in their breast milk. In addition, the women reported that their mastitis cleared after three weeks of taking the supplements. Subsequent trials studied whether probiotics were more effective at treating mastitis during breastfeeding compared with antibiotics.

Researchers have also found that even when not lactating, the breast microbiome exists. Researchers suspect that the bacteria in the breast might even play a role in disease, such as cancer. However, to study this link between the breast microbiome and health requires normalizing the microbiome, which is not an easy task. However, we do know that a healthy microbiome, whether a baby or mother’s harbor diverse bacteria. Researchers are just on the brink of discovering how diverse microbial communities affect our general health.

In addition to decreased abundances of Lactobacillus strains, the study also indicated higher levels of Ureaplasma and Gardnerella were tied to greater risks of premature labor.

If these results can be confirmed in larger studies, sequencing the vaginal microbiome throughout pregnancy might help determine women at high risk for preterm labor. Doctors may be able to use the vaginal microbiome as a diagnostic marker or tool to identify pregnancies that may have an increased risk of premature labor.

Finding the cause of Premature Birth

Researchers are not sure if the shifts in the vaginal microbiome are the only contributing cause for premature birth. However, they do believe that contributing factors for premature birth might also cause shifts within the vaginal microbiome.

Throughout the study, researchers observed the vaginal bacterial communities in 49 pregnant women aged 18 years and older weekly until after childbirth. The scientists sequenced the women's vaginas, gums, stool, and saliva. In this study, fifteen women experienced premature births.

Most women experienced a significant shift within the vaginal microbiome bacterial populations at the time of delivery. A wide range of bacteria replaced Lactobacillus strains, which were found in decreased abundances. This shift was observed for up to one year later in some women.

Researchers analyzed samples from the vaginal microbiome and other sites, discovering the vaginal bacterial communities shifted to become more similar to the gut microbiome shortly after delivery.

Although researchers are unsure how this shift affects the mother's health or how it actually happens, it is possible that shifts of bacteria communities in the vagina after childbirth might affect the risk of premature labor in a following pregnancy if conception occurs shortly after the previous delivery.

]]>Tue, 12 Apr 2016 14:54:16 +0000https://www.biome360.com/blog/premature-birth-linked-to-moms-microbiome/ https://www.biome360.com/blog/premature-birth-linked-to-moms-microbiome/ldavidson@omegabiotek.com (Dr. Kristen Senella)Dr. Kristen SenellaVaginal Microbiome Crucial to Development of NewbornsScientists have previously hypothesized that exposure to a mother's vaginal microbiome during birth is a critical step in forming a newborn’s microbiome. Neonates birthed by cesarean-section miss out on this initial exposure and are more likely to be exposed to and their guts then colonized by other bacteria in the local environment, including the mother’s skin and potential pathogens in the hospital. However, recent studies have indicated that the pregnant microbiome and her children’s may be modulated by stress, according to a study published in Endocrinology.

Although we still believe the neonate’s gut relies heavily on the maternal vaginal microbiome, shifts throughout pregnancy stemming from stress have altered the initial vaginal microbiome and determined the host’s immune response that is established throughout this delicate period.

Stress alters the vaginal microbiome

The study included pregnant mice that underwent stress tests utilizing predatory odors, unfamiliar sounds or restraints. After birth, researchers analyzed the bacterial communities of the mothers’ vaginal fluids and the pups’ colons. Interestingly enough, the results indicated that stress throughout pregnancy may disrupt several proteins associated with vaginal immunity and levels of Lactobacillus. Not surprisingly, this was associated to lower instances of Lactobacillus found within the neonate’s guts. Furthermore, male offspring from stressed mothers demonstrated increases in Bacteroidesin and Clostridium, anaerobic bacteria linked to dysbiosis.

These studies show enormous potential regarding the vaginal microbiome and birth, and how C-sections may potentially provide fewer benefits than natural birth to newborns. Some countries currently administer vaginal lavages orally to babies delivered by C-section to optimize exposure and increase immunity.

The research team calculated the free amino acids in the newborn brains to comprehend how they were influenced by the microbiome. Specific amino acid levels were observed to be reduced in male developing brains; however, this was not seen in female newborns. More research is required to understand the mechanisms behind the clear sex-specific effects and the link between the pregnant microbiome and newborn brain metabolism.

]]>Thu, 10 Mar 2016 14:33:04 +0000https://www.biome360.com/blog/vaginal-microbiome-crucial-to-development-of-newborns/ https://www.biome360.com/blog/vaginal-microbiome-crucial-to-development-of-newborns/ldavidson@omegabiotek.com (Dr. Kristen Senella)Dr. Kristen SenellaC-section Babies Get Microbiome TransplantBabies inherit a lot from their mothers, including genes, possible diseases, and even their microbes. However, since cesarean section babies do not pass through the birth canal, they lack essential bacteria that help fight disease and promote development. Researchers believe that the increasing epidemic of obesity, asthma, allergies, Type 1 diabetes, Celiac disease and other chronic diseases can be related to the rise in cesarean sections and disturbances in the microbiome during birth.

Human microbiome researchers have asked themselves if these disturbances can be prevented or fixed, which would help establish the microbes a baby would inherit naturally through vaginal birth.

A recent study published in Nature Medicine indicates that this idea has potential.

But how? Transplanting the microbes from the mother’s birth canal to a newborn can potentially partially establish and stabilize the microbiome that would naturally occur in babies during vaginal birth.

The researchers have emphasized that they need to study their results further to know the effectiveness and want to monitor the children throughout their lifetime to observe whether the intervention improves their health.

In the meantime, the researchers have emphasized that this should not be attempted at home because there is a risk dangerous pathogens could be transferred to the babies.

The women participating in the study were screened for known pathogens, including HIV and STIs, ahead of time and also given preventative antibiotics for group B Streptococcus (GBS) as a precaution, which is standard perinatal care.

"It's a very important study. It's showing that this is a possible intervention that might restore a health-promoting microbiome and lead to improved health outcomes for life," Juliette Madan, who studies babies’ microbiomes at Dartmouth Geisel School of Medicine, says.

The doctors involved in the study placed a piece of gauze inside the mother’s birth canal prior to birth via cesarean section, which soaked up their microbes. Once born, the doctors swabbed the babies with the gauze, concentrating on the mouth and face before moving onto the rest of their body.

The researchers sampled and analyzed the babies' microbes repeatedly during their first month and compared their microbiomes to C-section babies not swabbed, as well as babies born vaginally.

Reports show that the bacterial communities of the of the C-section babies’ mouths, guts and skin covered in their mother’s microbiome looked similar to those of babies delivered vaginally rather than C-section babies that did not receive the microbiome transplant.

Specific bacteria that were found in higher quantities included Lactobacillusand Bacteroides, which are considered beneficial bacteria. However, the C-section babies studies did not completely establish their microbiome as babies born vaginally.

Further research would follow babies for up to seven years to observe whether the intervention decreases disease risk. If the answer to this question is yes, a next-generation probiotic containing the bacteria babies need will be developed, which would also diminish the risk of transferring potentially dangerous microbes.

]]>Wed, 03 Feb 2016 17:14:37 +0000https://www.biome360.com/blog/c-section-babies-get-microbiome-transplant/ https://www.biome360.com/blog/c-section-babies-get-microbiome-transplant/ldavidson@omegabiotek.com (Dr. Kristen Senella)Dr. Kristen SenellaBaby’s microbiome established in womb, not birthScientists have recently explored the developing fetus and their microbiomes. Previously, doctors considered the womb sterile: the amniotic sac, and the fluid surrounding the baby, was a distinctively clean environment lacking bacteria or other microbial agents to defend the baby and the still developing immune system. Vaginal birth was considered the baby’s first exposure to bacteria, which continues after birth through skin-to-skin contact with mom and from its new environment.

However, current research supports the idea that the baby’s microbiome actually gets established much sooner than previously thought—in the womb. Scientists have detected small populations of bacteria in the amniotic fluid, placenta, and the fetus’ intestines.

Researchers aren’t exactly sure how this happens, but hypothesize that bacteria from the mother’s mouth might travel through the blood stream and reach the developing baby in utero through the placenta. Some bacteria might also travel from the vagina into the womb.

What exactly does this mean? Ultimately, the mother’s health and her microbes might have far greater influence on the baby’s health and development, including vulnerability to disease, than we previously thought. One researcher thinks it might indicate that establishment of the baby’s microbiome begins in utero and can be influenced by the health and diet of the mother during pregnancy. Other studies have found that overweight mothers have different types of bacteria in their gut than those of normal weight mothers, and an expectant mom’s dental health could also have an effect on her baby’s microbiome and later health.

The researchers have stressed it is still early to know the “right” microbiome that’s conducive to a healthy baby, or a “wrong” one that might lead to disease. However, there are certainly things like maternal dental hygiene and not taking unnecessary antibiotics that should be considered. We knew it was important to be healthy during pregnancy, but now, the research indicates how important the mother’s microbiome is.

]]>Mon, 28 Dec 2015 19:10:36 +0000https://www.biome360.com/blog/babys-microbiome-established-in-womb-not-birth/ https://www.biome360.com/blog/babys-microbiome-established-in-womb-not-birth/ldavidson@omegabiotek.com (Dr. Kristen Senella)Dr. Kristen SenellaGut Bacteria Make Us Obese or LeanOne-third of Americans struggle with obesity due to lifestyle choices like diet, exercise and genetics; however, after years of studies indicating a correlation, researchers have become increasingly convinced that the gut microbiome plays an important role in obesity.

Throughout human history, we have been home to these bacteria of our intestines, which evolved to help us digest tough plant fibers in exchange for a home. Now, scientists realize their roles extend beyond the digestive system. Novel research indicates that our microbiome alters fat storage and how we respond to hormones, and balances glucose in the blood. Dysbiosis, or an unbalanced gut can potentially lead to obesity and diabetes from the moment of birth.

Researchers now recognize the differences between dysbiosis and a balanced gut, as well as the factors that shape those differences. They hope to study how to cultivate this inner ecosystem in ways that could prevent and potentially treat obesity, which doctors define as having a particular body mass index (BMI) that is greater than 30. Imagine, for example, foods, baby formulas or supplements devised to promote virtuous microbes while suppressing the harmful types. Keeping our gut microbes balanced might be the secret to weight control.